WorkIsolate<P extends SendPort2> class abstract

An isolated Dart execution context.

All Dart code runs in an isolate, and code can access classes and values only from the same isolate. Different isolates can communicate by sending values through ports (see ReceivePort2, SendPort2).

An Isolate object is a reference to an isolate, usually different from the current isolate. It represents, and can be used to control, the other isolate.

When spawning a new isolate, the spawning isolate receives an Isolate object representing the new isolate when the spawn operation succeeds.

Isolates run code in its own event loop, and each event may run smaller tasks in a nested microtask queue.

An Isolate object allows other isolates to control the event loop of the isolate that it represents, and to inspect the isolate, for example by pausing the isolate or by getting events when the isolate has an uncaught error.

The controlPort identifies and gives access to controlling the isolate, and the pauseCapability and terminateCapability guard access to some control operations. For example, calling pause on an Isolate object created without a pauseCapability, has no effect.

The Isolate object provided by a spawn operation will have the control port and capabilities needed to control the isolate. New isolate objects can be created without some of these capabilities if necessary, using the WorkIsolate.Isolate constructor.

An Isolate object cannot be sent over a SendPort, but the control port and capabilities can be sent, and can be used to create a new functioning Isolate object in the receiving port's isolate.

Implementers

Constructors

WorkIsolate(SendPort2 controlPort, {Capability2? pauseCapability, Capability2? terminateCapability})

Properties

controlPort → SendPort2: Control port used to send control messages to the isolate.
final
debugName → String?: The name of the WorkIsolate displayed for debug purposes.
no setter
hashCode → int: The hash code for this object.
no setterinherited
messages → Stream: Returns a broadcast stream of uncaught errors from the isolate.
no setter
pauseCapability → Capability2?: Capability granting the ability to pause the isolate.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
terminateCapability → Capability2?: Capability granting the ability to terminate the isolate.
final

Methods

addErrorListener(SendPort2 port) → void: Requests that uncaught errors of the isolate are sent back to port.
addOnExitListener(SendPort2 responsePort, {Object? response}) → void: Requests an exit message on responsePort when the isolate terminates.
kill({int priority = beforeNextEvent}) → void: Requests the isolate to shut down.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
pause([Capability2? resumeCapability]) → Capability2: Requests the isolate to pause.
ping(SendPort2 responsePort, {Object? response, int priority = immediate}) → void: Requests that the isolate send response on the responsePort.
removeErrorListener(SendPort2 port) → void: Stops listening for uncaught errors from the isolate.
removeOnExitListener(SendPort2 responsePort) → void: Stops listening for exit messages from the isolate.
resume(Capability2 resumeCapability) → void: Resumes a paused isolate.
sendToIsolate(Object message) → void
setErrorsFatal(bool errorsAreFatal) → void: Sets whether uncaught errors will terminate the isolate.
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Constants

beforeNextEvent → const int: Argument to ping and kill: Ask for action before the next event.
immediate → const int: Argument to ping and kill: Ask for immediate action.